There are so many different diets out there that claim to help with weight loss and disease prevention: low-fat, low-carb, ketogenic, paleo, whole 30, vegetarian, vegan, DASH, Mediterranean, MIND, etc. Today, I will be focusing on one of the most recent trends: intermittent fasting.
You may be accustomed to eating three meals and snacks per day. That is quite common. With intermittent fasting, you can eat pretty much whatever you want – but there’s a catch: you have to stick to a schedule. There are times when you can eat and times when you must fast when you practice intermittent fasting. Intermittent fasting, unlike most other diets, teaches you when to eat rather than what to consume.
Many people believe it can help you achieve better health and live longer.
Let’s look at some of the benefits and drawbacks of intermittent fasting.
How to intermittently fast
The majority of weight-loss regimens operate by lowering the number of calories consumed. Intermittent fasting accomplishes the same goal in a different manner. This type of eating restricts calories (requires fasting) for short periods of time (intermittently), but allows little or no limitations the rest of the time.
Intermittent fasting is when you skip meals on a regular basis, whether it’s daily, weekly, or monthly. Here are some examples of alternative approaches:
- Time-restricted feeding— All of your meals are during an 8 to 12-hour window each day, drinking only water the rest of the day.
- Alternate day fasting—Eating normally one day but only a limited amount of calories the next; alternating between “feast” days and “fast” days.
- 5:2 eating pattern—Consuming meals regularly for five days per week, then restricting to no more than 600 calories per day for the other two. This happens by eating very little and drinking only water on those two fasting days.
- Periodic fasting—Caloric intake is restricted for several consecutive days and unrestricted on all other days. For example, fasting for five straight days per month.
Benefits of intermittent fasting
Studies show that intermittent fasting can achieve weight loss. The results are similar to other diets. (Yes, similar—not necessarily better).
Overall, research into the effects of intermittent fasting on people’s health is currently ongoing, with the goal of determining if, in addition to weight loss, it can also prevent disease or reduce aging in some people.
The majority of calorie restriction and intermittent fasting research has been done in cells (such as yeasts), rats, and even primates. Some, but not all, of this research suggest that it may aid in the development of exercise endurance, immune function, and the ability to live longer. It also appears to aid in the prevention of diseases such as diabetes, heart disease, some cancers, and Alzheimer’s disease.
When it comes to the clinical trials on intermittent fasting (those conducted on people) have been brief—a few months or less. However, what we do know is that it may help with inflammatory markers (C-reactive protein), diabetes (blood glucose levels and insulin sensitivity), and high blood pressure and cholesterol reduction.
When it comes to weight loss, intermittent fasting seems to work comparably well—not better—than other diets. Researchers believe that eating this way slows down the body’s metabolism and reduces appetite. When you lose your appetite, you eat less, which will help you lose weight. Others who fast intermittently struggle with fasting days and feel uncomfortable all the time, and some animal studies show that many are overeating when they are allowed to eat as much as they want.
What about extending the lifespan of humans? Those studies haven’t been done yet, so we simply don’t know the effects of intermittent fasting on our lifespan.
How intermittent fasting affects your health
Our body has a survival mechanism that can adapt to the fasting period. This has been necessary because throughout history people have experienced many times of food shortages.
What happens if we don’t eat enough calories? Our body begins to use stored carbohydrates called glycogen. The liver stores enough glycogen that will last about 12-16 hours before it runs out of fuel. After 16 hours, the body switches fuel and begins to use fat as energy.
At this point, our metabolism shifts from a carbohydrate-burning state to a fat-burning state. Some of the fat is used directly as fuel, but some are metabolized into biochemicals called ketones. This new fat-burning metabolic state is known as ketosis. The state of ketosis causes other changes throughout the body. These changes are believed to underlie some of the health benefits of intermittent fasting.
Ketones are a more efficient source of energy for our body than glucose and can therefore help many cells to function well during fasting. This is especially true for brain cells, which may be one of the reasons why some animal studies show protection against age-related decline such as Alzheimer’s disease.
Ketones may also help prevent some cancers and inflammatory diseases such as arthritis. It is also thought to reduce the amount of insulin in the blood and may help protect against type 2 diabetes. On the other hand, too many ketones can be harmful, so more research is needed to better understand the link between fasting, ketones, and health.
At the molecular level, intermittent fasting affects the DNA of our genes, which can extend the lifespan of animals. Over time, as we grow older, the way our genes are turned on and off changes. Calorie restriction seems to delay these age-related changes and help them live a little longer.
Further research is underway to better understand the effects of fasting on these biological processes.
Before you start intermittently fasting
As with any other major dietary change, be sure to talk to your doctor or book a consultation with me here to get started on the right plan for you.
Before considering intermittent fasting, you need to be aware that there are certain conditions that are dangerous. For example, if you have diabetes, fasting is not recommended because you need to eat regularly to maintain your blood sugar. Intermittent fasting increases the risk of electrolyte imbalances, so if you are taking certain medications, such as high blood pressure or diuretics for heart disease, there is a risk.
Intermittent fasting is also not recommended for people under the age of 18, those who have a history of eating disorders, or anyone that is pregnant or breastfeeding.
Of course, side effects can be caused by dietary changes. Some of the side effects experienced by people who limit calorie intake or start intermittent fasting include fatigue, weakness, headaches, decreased sexual interest and decreased ability to maintain body temperature in cold environments.
Aside from health risks and side effects, it is difficult to fast voluntarily. Especially if it’s more than 2 days. Some people tend to indulge on their “feast” days, which can negate some of the benefits of fasting.
The National Institutes of Health has stated, “More research will be needed to determine the long-term impact of the diet on human health and provide information on when and how such a diet might be applied.”
Nutrition tips for intermittent fasting
Intermittent fasting can be quite difficult. One thing that can help is having a social support network—especially for the days of fasting.
Although the basis of intermittent fasting is to restrict when you eat, not what you eat, the quality of the food choices remains an important factor. Regardless of your style of eating and preferences, you continue to need all of the essential nutrients. Intermittent fasting is not a reason to consume loads of the high-calorie nutrient-poor foods we all tend to crave. I recommend consuming adequate amounts of lean proteins, healthy fats, fruits, vegetables, legumes, and whole grains. Also, keep away from too many sugars and refined grains.
Check out this amazing recipe that contains a high-quality protein and lots of nutrients from the veggies. Feel free to change up the veggies!
The main goal for any dietary change is to have a healthy and sustainable lifestyle that will help you meet your individual health goals. Whether you are wanting to lose weight or prevent disease, intermittent fasting is an eating style that may work for you. The most important thing to consider with your diet is to get all of the essential nutrients, eat adequate amounts of food, and enjoy your lifestyle.
There is no “one size fits all” when it comes to a diet. Any diet or eating pattern that helps some people may not have the same effect on everyone. That’s why it’s important to not make any significant dietary changes without consulting your healthcare professional or dietitian.
If you’re looking for the right diet for you, book an appointment with me to see if my service can help you.
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